1. Field of the Invention
The present invention related to a semiconductor package device, and more particularly to a semiconductor package device with a cavity structure therein.
2. Description of the Prior Art
Please refer to FIG. 1, shows a cross-sectional view of conventional ball grid array (BGA) package device. The BGA package device 100 includes semiconductor die 120 which is disposed on substrate 110 or carrier substrate 110, and is electrically connected carrier substrate 110 via the plurality of conductive wires 130. A plurality of connecting components 150 is disposed on the top surface of carrier substrate 110.
Unfortunately, in the conventional package technology, package material 140 such as epoxy resin with higher dielectric constant (the dielectric constant k is over 2) will interfere the millimeter wave that is generated from the package device when the epoxy resin is contacted directly with the package device with high sensitive such as Applicant-specific integrated circuit (ASIC) device. The epoxy resin with high dielectric constant will change the signal wave-conduction speed, and the signal decay is to be occurred during the wave-conduction. When the wave is conducted to pass through different materials, the wave-conduction speed would be different between the different materials with different dielectric constants, so as to the signal distortion would be generated. The selection for the material 140 of package body must be avoided by using the high dielectric constant material to prevent the signal distortion. However, the plurality of conductive wires is formed by wire bonding process within the package structure which needs the epoxy molding compound to protect the plurality of conductive wires, in which the dielectric constant of the epoxy molding compound is usually larger than 4, so that the signal distortion would be existed.